Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Egan's Ch. 13
Acid-Base Balance
| Question | Answer |
|---|---|
| what is the state called in which arterial blood is more acidic than normal? aka increased concentration of hydrogen ions. | acidemia |
| what is the difference called between the normal buffer base and the actual buffer base in a whole blood sample? | base excess (BE) |
| what is alkalemia? | decreased hydrogen ion concentration in the blood; blood pH greater than 7.45 |
| how is BE expressed? | mEq/L |
| what is the normal BE? | +2 mEq/L |
| what is the buffer base? | the total blood buffer capable of binding hydrogen ions |
| what is the normal blood buffer base (NBB) range? | 48-52 mEq/L |
| what is a titrable, nonvolitile acid called? | fixed acid |
| what does a fixed acid represent? | the by-product of protein catabolism |
| what kind of acids are phosphoric acid and sulfuric acid? | fixed |
| what is the Henderson-Hasselbalch (H-H) equation? | the specific equation for calculating the pH of the bicarbonate buffer system of the blood |
| what does pH = 6.1 + log HCO3-/(PaCO2 x 0.03) represent? | H-H equation |
| what is the importance of the H-H equation? | it equals the pH of blood plasma, and since all buffer systems in the blood are in equilibrium, the pH of one system equals the pH of the entire plasma solution. |
| what is hypercapnia? | excess amounts of CO2 in the blood (PaCO2) |
| what is the presence of lower than normal amounts of CO2 in the blood (PaCO2)? | hypocapnia |
| define metabolic acidosis? | non-respiratory processes resulting in acidemia |
| what is called when non-respiratory processes, such as losing fixed acid or gaining HCO3-, result in alkalemia? | metabolic alkalosis |
| define respiratory acidosis. | hypoventilation, the loss of HCO3- or gaining fixed acids resulting in acidemia |
| define respiratory alkalosis? | hyperventilation, resulting in alkalemia |
| the plasma concentration of HCO3- that exists if PCO2 is normal is known as ____ | standard bicarbonate |
| how is standard bicarbonate expressed? | mEq/L |
| What is the PCO2 baseline for standard bicarbonate? | 40 mm Hg |
| what is an acid that can be excreted in its gaseous form? | volatile acid |
| what is a physiological example of a volatile acid? | carbonic acid |
| how much CO2 does normal ventilation eliminate everyday? | 24,000 mmol/L total 13,000 mmol/L of volatile |
| effect of small changes in the hydrogen ion concentration? | failure of vital metabolic processes |
| what continuously generates H+? | normal metabolism |
| H+ regulation is of utmost biological importance? T or F | true |
| various physiological mechanisms regulate ____ in a range compatible with life ( aka acid-base balance). | the H+ concentration of body fluids |
| what property of H+ is the reason for the need to regulate its concentration? | it reacts readily with the protein molecules of vital cellular catalytic enzeymes |
| why can H+ be dangerous? | its reactions with proteins can change their physical contour, rendering the enzyme inactive |
| wat is the normal, life sustaining, pH range of the body? | 7.35-7.45 |
| what would be the results of an ABG if patient is hypoventilating? (uncompensated) | pH - less than 7.35 PaCO2 - greater than 45 HCO3 - 22-26 respiratory acidosis |
| what gas is carbonic acid (H2CO3) in equilibrium with? | dissolved CO2 |
| what would be the results of an ABG if the patient is hyperventilating? (uncompensated) | pH - greater than 7.45 PaCO2 - less than 35 HCO3 - 22-26 respiratory alkalosis |
| HHb= Hb- + H+ | Hb buffering/transporting H+ |
| H+ + HCO3-= H2CO3 | carbonic acid, bicarbonate + hydrogen ion |
| interpret the ABG: pH- 7.2 PaCO2- 30 HCO3- 15 | partial compensated metabolic acidosis |
| what are the 2 major mechanisms responsible for maintaining a stable pH despite CO2 production? | isohydric buffering and ventilation |
| interpret the ABG: pH- 7.52 PaCO2- 40 HCO3- 30 | uncompensated metabolic alkalosis |
| on a pH-CO2 diagram showing the hydration reaction between CO2 and H2O, if theres is an increase of CO2 from 40 to 80 what happens to the value of the HCO3? | it increases from 24 to approximately 28.5 |
| what disease can increases fixed acid production? | diabetes |
| how does the respiratory system compensate for increased fixed and volatile acid production? | ventilation |
| how do the kidneys compensate for respiratory acidosis? | by reabsorbing HCO3 back into the blood |
| what can be done to correct respiratory acidosis and improve alveolar ventilation? | bronchial hygiene,lung expansion, non-invasive PPV, intubation, mechanical ventilation |
| what are some signs of respiratory alkalosis? | paresthesia, dizziness, headache, hyperventilation |
| how do the kidneys compensate for respiratory alkalosis? | by excreting HCO3 in the urine |
| what is a buffer solution? | a mixture of acids and bases that resist changes in pH when an acid or a base gets added to it |
| how are blood buffers classified? | as either bicarbonate (open) or non-bicarbonate (closed) buffer systems |
| what does the bicarbonate (open) buffer system consist of? | H2CO3 and a conjugate base of HCO3- |
| what does the non-bicarbonate (closed) buffer system consist of? | phosphates and proteins, including Hb |
| what is the main function difference in between an open and closed buffer system? | open- removes components of acid-base reactions through ventilation closed- all components of acid-base reactions remain in the system |
| in a closed buffer system, when does buffering activity stop? | when Hbuf reaches equilibrium with the reactants |
| what can be done to correct respiratory alkalosis? | O2 therapy |
| examples of open buffer systems | plasma erythrocytes |
| examples of closed buffer systems | Hb, organic and inorganic phosphates, and plasma proteins |
| what acids acids does a closed buffer system buffer? | volatile and fixed |
| what acids acids does an open buffer system buffer? | fixed, only when ventilation is not impaired, plus any individual H+ regardless of origin |
| which has the greater buffering capacity, a closed or open system? | open |
| open and closed buffer systems function in isolation. T or F | false, they are intermingled in the same solution (whole blood) and are equal in pH (isohydric principle) |
| in which 2 ways can metabolic acidosis occur? | acid accumulation in the blood or excessive loss of HCO3 |
| what is the normal anion gap range? | 8-16 |
| what does the buffering of a fixed acid produce? | CO2 |
| what is the most important non-bicarbonate buffer system? why? | Hb it is the most abundant |
| what is the common blood fluid compartment that both open and closed buffer systems function? | blood plasma |
| what are the primary acid excreting organs? | lungs and kidneys |
| which is faster at removing acid, lungs or kidneys? | lungs |
| if one acid-excretion system fails, the other will compensate. T or F | true; especially in diseased individuals |
| why is CO2 elimination crucial? | it reacts with H2O to form large quantities of H2CO3 |
| what is the anion gap? | the calculation of 4 electrolytes (Na+, Cl-, K+, and HCO3-) |
| why is the H-H equation useful in a clinical setting? | you can use it to see if the pH, PCO2, and HCO3 values for an abg are compatible; prevents transcription errors amd analyzer inaccuracies; also, to predict the result of changing the value of one or more of the variable |
| what is the purpose of using the anion gap? | to eliminate the effects of respiratory involvement; aka to see whats going on at the metabolic level |
| what is indicated by an anion gap >16? | metabolic acidosis |
| what are some of the causes on high anion gap metabolic acidosis? | lactic acidosis, ketoacidosis, renal failure. aspirin, formic acid, ethylene glycol |
| what are some of the causes of normal anion gap metabolic acidosis? | diarrhea, pancreatic fistula. renal tubular acidosis. ammonium chloride, hyperalimentation intravenous nutrition |
| what are some of the symptoms of metabolic acidosis? | dyspnea,hyperpnea, Kussmaul's breathing, lethargy, coma |
| at what pH are severe cardiac arrhythmias likely? | below 7.2 |
| what are ways to correct metabolic acidosis? | if above 7.2, nothing, dr. will need to treat underlying condition if below 7.2, intravenous infusion of NaHCO3 |
| how do the lungs compensate for metabolic acidosis? | hyperventilation |
| what factor determines how much H+ is removed by the kidneys? | blood pH |
| how much fixed acid is excreted per day by the kidneys? | <100 mEg |
| the kidneys also regulate HCO3 levels. T or F | true; when large amounts of H+ are excreted, the HCO3 is reabsorbed back into the blood and vice vera |
| in what 2 ways can metabolic alkalosis occur? | loss of fixed acids or gain of blood buffer base; either one increases plasma HCO3 |
| what is the most complicated acid-base imbalance to treat? | metabolic alkalosis; it involves fluid and electrolyte imbalances |
| what is the goal of secreting less H+? | to increase the amount of HCO3- in the urine, increase the amount of H+ in the blood |
| what is the goal of secreting more H+? | to increase the amount of HCO3- in the blood, decrease the amount of H+ in the blood |
| what happens when filtrate pH reaches 4.5? | secretion ceases to function and H+ secretion stops |
| what are some of the causes of metabolic alkalosis? | vomiting, hypokalemia |
| how do the lungs compensate for metabolic alkalosis? | by hypoventilating |
| what is the normal range of arterial bicarbonate? | 22-26 mEq/L |
| What maintains bicarbonate levels? | kidneys |
| what maintains CO2 levels? | lungs |
| what is the ratio of HCO3- buffer/dissolved CO2 that maintains a normal pH? | 20:1 |
| when ___ increases or ___ decreases, it leads to alkalemia.(ratio greater than 20:1) | HCO3- PCO2 |
| a decrease in ___ or an increase in ___ leads to acidemia. (ratio less than 20:1) | HCO3- PCO2 |
| pH changes caused by PaCO2 are referred to as what? | primary respiratory disturbances |
| what are some ways to correct metabolic alkalosis? | increased intake of fluids containing Cl-; in hypokalemia- administering KCl (potassium chloride) if severe- HCl or ammonium chloride |
| how does the hydration reaction produce HCO3? | CO2 and H20 create H2CO3, Hb snatches the H+, thus resulting in HCO3 CO2+H2O-->H2CO3-->HCO3- | Hb+H-->HHb |
| how much does plasma HCO3 increase with acute increase in PCO2? | about 1 mEq/L for every 10 mm Hg increment over 40 |
| what is the first step to analyzing acid-base problems? | categorizing pH pH scale |
| what is the second step in analyzing acid-base problems? | determining respiratory involvement PaCO2 |
| what is the third step in analyzing acid-base problems? | determine metabolic involvement plasma HCO3- |
| what is the last step in analyzing acid-base problems? | assess for compensation |
| what are some of the causes of respiratory acidosis? | anesthesia, narcotics, and sedatives poliomyelitis, myasthenia gravis, guillian-barre syndrome trauma to spinal cord, brain, chest wall, kyphoscoliosis, obesity COPD, airway obstruction |
| what are some of the causes of respiratory alkalosis? | anxiety, fear, stimulant drugs, CNS lesion, pain, sepsis hypoxemia, asthma, pneumonia, pulmonary edema, pulmonary vascular disease latrogenic hyper ventilation |
| how do u calculate base excess? | add all positive ions (cations) then add all negative ions (anions) then find the difference between the two (in mEq/L) |
Created by:
sarah72388
Popular Respiratory Therapy sets